Low-Hysteresis and Lineear Piezoelectric Actuator made from Ultra-fine Particles

由超细颗粒制成的低磁滞线性压电执行器

基本信息

批准号：
03650010
负责人：
ISHIKAWA Kenji
金额：
$ 1.15万
依托单位：
Research Institute of Electronics, Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

Crystals generally show different characteristics from bulk crystals when their sizes become an order of nanometer. We have been studying this 'size effect' in ferroelectric fine particles for several years and found that the crystal size affects the domain wall movements or the crystallizing process,which establishes a method to synthesize ultra-fine particles. In the present work, we have attempted to improve the hysteresis phenomena or the non-linearity appeared in the relation between the displacement and the applied voltage in piezoelectric PZT actuators. Lead, titanium, and zirconium alkoxides are dissolved in an organic solvent. Hydrolyzing the solution gives PZT fine particles which are still in amorphous state. The amorphous fine particles can be crystallized through the heating at 600ﾟC in air for 5h. The crystallizing temperature is much lower than that of bulk crystals(1280 ﾟC). The lowered temperature enables to obtain ceramics of stoichiometric composition because lead does not evaporate at this temperature. Fine particles obtained are calcined through HIP(hot isostatic pressing) to form a ceramic disc. The ceramic form fine-particles shows quite small hysteresis of an order of 1%, much less than that of conventional ceramics(about 10 %). A typical size of the small particles composing our ceramics is found to be several hundreds nanometers by SEM observation. The size is not still enough small, however, to inhibit the domain wall movement. High resolution TEM observations suggest that fine structures of several nanometers exist in the particles. Thus, the fine structure seems to be 'traces' of boundary of starting powders and should act as pinning points of the wall movement.

当晶体大小成为纳米级时，晶体通常显示出与大块晶体不同的特征。我们已经在铁电细颗粒中研究了这种“尺寸效应”已有几年了，发现晶体尺寸会影响域壁的运动或结晶过程，该过程建立了一种合成超细颗粒的方法。在目前的工作中，我们试图改善滞后现象或在压电PZT执行器中的位移与施加电压之间的关系中出现的非线性。铅，钛和锆烷氧化物溶解在有机溶液中。水解溶液会产生仍处于无定形状态的PZT细颗粒。无定形的细颗粒可以通过在空气中的600°C的加热中结晶5小时。结晶温度远低于散装晶体（1280 c）的温度。降低的温度使得可以获得化学计量组合物的陶瓷，因为铅在该温度下不会蒸发。通过臀部（热等静力压）钙化所获得的细颗粒以形成陶瓷盘。陶瓷形成的细粒子显示出1％的序列相当小，远小于常规陶瓷（约10％）。通过SEM观察，发现组成我们陶瓷的小颗粒的典型尺寸是数百个纳米。但是，尺寸还不够小，无法抑制域壁运动。高分辨率TEM观察结果表明，颗粒中存在几种纳米的细胞结构。那就好的结构似乎是起始粉末边界的“痕迹”，应该充当墙运动的固定点。